Dyadic Green’s Functions for Homogenized Bianisotropic Planar Metasurfaces Placed at Two Half-Space Interface

In this article, we present the dyadic Green’s functions (DGFs) for the most general homogenized bianisotropic planar metasurface (MS) placed at a two half-space interface. To achieve this, we employ the full-tensor generalized sheet transition conditions (FT-GSTCs), which involve a total of 36 susceptibility parameters. The theory of finding the DGFs is based on the Ohm-Rayleigh method and the scattering superposition principle (SSP). The derived DGFs can be used to obtain the electromagnetic (EM) fields in each half-space due to any arbitrary current source distribution. By applying the GSTCs, we also present the DGFs for a bianisotropic MS homogenized by 20-parameter antisymmetric susceptibility tensors. In this case, the DGFs exhibit specific $\phi $ -variations, leading to simplified expressions in cylindrical coordinates. Using the derived DGFs, we present general expressions of total electric fields due to arbitrarily oriented infinitesimal electric dipoles and plane wave (PW) illumination. Practical examples of planar MSs residing on an air-dielectric interface are considered, and the results are compared with those obtained from integral equation (IE)-based commercial software to demonstrate the efficiency of the DGF approach. We believe that the results of the current study provide an effective tool to push the analysis of bianisotropic MSs one step forward.